# Mark Williamson

> Mark Williamson is a seed investor backing Mobile and Collaboration. See 16 investments, check sizes, portfolio and contact details. Updated Aug 2026.

- Type: Angel Investor
- Location: San Francisco, United States
- Total investments: 16
- Last investment: Jun 2022
- Lead investor: 0%
- Last updated: Aug 2026
- LinkedIn: http://www.linkedin.com/in/mwilliamson
- X (Twitter): http://twitter.com/WilliamsonMark
- Website: https://x.com/WilliamsonMark
- Facebook: http://www.facebook.com/mark.williamson

Mark Williamson is a seed investor in San Francisco focused on Mobile and Collaboration. Mark Williamson is based out of Los Altos, California and is the Board of Directors of MasterClass. Mark previously worked at RestoreHealth as a CEO & Co-founder. Mark Williamson attended the MIT Sloan School of Management.

## Contacts

5 contacts available for Mark Williamson: work email, personal email, work phone, personal phone and socials. Sign up free to unlock them: https://app.shizune.co/sign-up/investor-profiles/find-email/mark-williamson-2?utm_source=investor_profile

## Round sizes

| Stage | Round size |
| --- | --- |
| Seed | $500k–$5M |

## Investment focus

### Industry

| Industry | Investments | Share |
| --- | --- | --- |
| Mobile | 5 | 31% |
| Collaboration | 3 | 19% |
| Enterprise Software | 3 | 19% |
| Software | 2 | 13% |
| Messaging | 2 | 13% |

33 industries tracked in total.

### Stage

| Stage | Investments | Share |
| --- | --- | --- |
| Seed | 8 | 50% |
| Series A | 2 | 13% |
| Series B | 1 | 6% |
| Series C | 1 | 6% |
| Funding Round | 1 | 6% |

### Country

| Country | Investments | Share |
| --- | --- | --- |
| United States | 9 | 56% |
| Poland | 1 | 6% |
| United Kingdom | 1 | 6% |

## Investments

| Company | Description | Amount | Stage | Date | Website |
| --- | --- | --- | --- | --- | --- |
| Xip | Xip provides a personalised learning experience that transforms how people learn online. | $5M | Seed | Jun 15, 2022 | https://xip.co |
| Hivemapper | Build a better map together | $18M | Series A | Apr 05, 2022 | http://hivemapper.com/ |
| Tylko | Tylko offers uncompromising quality at a fair price, while perfectly fitted to your space & easily ordered online. | $26M | Series C | Mar 23, 2021 | http://tylko.com/ |
| Fieldwire | Fieldwire is the field management platform construction pros count on to easily manage the job site.Construction companies of all sizes use Fieldwire to power clear communication on over 500,000 projects worldwide. With its easy-to-use mobile application, Fieldwire saves each user 1 hour every day by enabling more efficient information sharingonsite. Fieldwire’s key features include plan viewing, task management, issue tracking, reporting, and more — all accessible from one place. Fieldwire is venture-backed by top investors in the industry and is already transforming the way dispersed teams communicate and collaborate on projects. Fieldwire is the easiest way for construction companies to stay organized on the job site. |  | Seed | Feb 05, 2015 | https://www.fieldwire.com |
| Spool | Spool saves your favorite articles and videos to your computer, tablet, and phone. Read and watch your content when you have time, even offline. |  | Seed | Jan 01, 2015 | http://getspool.com/ |
| Fieldwire | Fieldwire is the field management platform construction pros count on to easily manage the job site.Construction companies of all sizes use Fieldwire to power clear communication on over 500,000 projects worldwide. With its easy-to-use mobile application, Fieldwire saves each user 1 hour every day by enabling more efficient information sharingonsite. Fieldwire’s key features include plan viewing, task management, issue tracking, reporting, and more — all accessible from one place. Fieldwire is venture-backed by top investors in the industry and is already transforming the way dispersed teams communicate and collaborate on projects. Fieldwire is the easiest way for construction companies to stay organized on the job site. |  | Seed | Jan 01, 2015 | https://www.fieldwire.com |
| SendHub | SendHub is the Phone System for the Mobile World. There's no hardware, setup is instant and it scales elastically with a single click. Users are given a phone number in any area code, they can use from any device: Web, iPhone, Android, Feature Phones and via our API.Businesses can add lines for everyone on their team for free, withcomplete transparency and powerful analytics on every aspect of your telecommunication.Additional Features: Auto Attendant, Call Transfer, Company Directory, Contact Sharing, Voicemail Transcription, Text Marketing & Group Texting, Free Internal Communication. |  |  | Jan 01, 2015 | http://sendhub.com |
| Tule | Tule provides you with Actual ET data to inform your irrigation decisions. This technology, developed and licensed from UC Davis, is the only commercially available technology for measuring actual evapotranspiration. One Tule sensor measures evapotranspiration over a 1 to 10 acre area, not just at one individual plant. The sensor remotely reportsdata back to the Tule dashboard, providing actionable information for your irrigation decisions on a daily basis. Weekly reports include a forecast of the atmospheric demand for the upcoming week to aid in planning your irrigation schedules.Tule features include:• 24/7 Evapotranspiration Monitoring: see how much water is used by your entire field and applied by your irrigation system every day, without visiting each block.• Field-level Water Stress Tracking: know if your plants are getting the right amount of water at the right time to achieve your production goals.• Compare Performance Across Fields: see how your irrigation decisions impact your plants and compare your fields to sites managed by other growers in your region. |  | Seed | Jan 01, 2015 | https://www.tuletechnologies.com/ |
| Kamcord | Kamcord is a social media platform allowing its users to post and interact through video content. The company is based in San Francisco, California. | $15M | Series B | Dec 11, 2014 | http://www.kamcord.com |
| Kamcord | Kamcord is a social media platform allowing its users to post and interact through video content. The company is based in San Francisco, California. |  | Series A | May 01, 2014 | http://www.kamcord.com |

10 of 16 investments shown.

## Co-investors
- [Merus Capital](https://shizune.co/investors/profile/merus-capital) — VC Fund, 2 deals together
- [TDJ Pitango Ventures](https://shizune.co/investors/profile/tdj-pitango-ventures) — VC Fund, 2 deals together
- [Translink Capital](https://shizune.co/investors/profile/translink-capital) — VC Fund, 2 deals together
- [Wargaming](https://shizune.co/investors/profile/wargaming) — VC Fund, 2 deals together
- [75 & Sunny](https://shizune.co/investors/profile/75-sunny) — VC Fund, 1 deal together
- [Accelerator Ventures](https://shizune.co/investors/profile/accelerator-ventures) — VC Fund, 1 deal together

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## FAQ

### What does Mark Williamson invest in?

Mark Williamson invests primarily in Mobile, Collaboration and Enterprise Software startups, most often at Seed and Series A stage. Most of the 16 investments tracked by Shizune back companies in United States. The Investment Focus section breaks down every industry, stage and country in the portfolio.

### What is Mark Williamson's check size?

Mark Williamson typically joins rounds of $500k–$5M at Seed. These ranges are 10th–90th percentile round sizes calculated from confirmed public funding rounds, so they are a realistic guide to the rounds Mark Williamson participates in.

### How do I contact Mark Williamson?

Public channels for Mark Williamson include LinkedIn, X (Twitter) and the website linked on this profile. For a verified work email and phone number, create a free Shizune account — contact data is searched across 20+ sources and validated before delivery, so your outreach lands in the right inbox.

### When did Mark Williamson last invest?

The most recent investment recorded for Mark Williamson closed in Jun 2022. Shizune tracks 16 investments in total for this profile, including round sizes, stages and portfolio companies, all sourced from confirmed public funding rounds and refreshed monthly.

### Is Shizune's investor data accurate?

Yes — every stat on this profile is calculated from confirmed public funding rounds monitored across hundreds of sources since 2020. This profile was last refreshed in Aug 2026 and is updated monthly. Spotted something off? Use the “Suggest an edit” link near the top of the page.

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