I’m [David Baldwynn](https://github.com/whitef0x0/tellform), an open source advocate and [Node.js](https://www.sparkpost.com/blog/using-node-js-for-reporting/) developer. I’m also the creator of Tellform, a [free, open source](https://www.tellform.com/) form builder similar to Google Forms or TypeForm. TellForm spawned out of a contracting project for a medical client that required on-site hosting of a kiosk form app. After a few weeks of building a simple kiosk form app, I decided I wanted to make my app reusable. So last summer I created a dynamic, self-hostable form builder that was to become TellForm.

After working on **TellForm** for a couple of months, I decided to open source it in September 2015. Despite the slow initial launch with only a few users per day, I used my existing users to iterate and improve TellForm. This led to the adding of multiple new features, including the Google Analytics integration and the built-in form analytics page. As one of the few UX/UI focused open source form builders out there, I also sought advice from designers and continued to iterate on the form design. Thus, I added animated scrolling and user-friendly input validation to my form.

HackerNews ended up posting about **TellForm**, which then led to Product Hunt hunting it. These events further legitimized TellForm and increased the project’s awareness. This brought more views and with it a designer, Arun Pattnaik, to join my team permanently.

## SparkPost + TellForm

As a web developer, I wasn’t initially aware of SparkPost. However, I had to look for an alternative email API to power my email signup verification process during [Mandrill’s cessation of their free tier](http://blog.mandrill.com/important-changes-to-mandrill.html). After looking for over a month I settled on SparkPost. Its [generous free tier](http://pages.sparkpost.com/2016-Social-Bl-pricing.html?utm_source=blog&utm_medium=social-media&utm_campaign=bl-tellform), paired with its [great documentation](http://developers.sparkpost.com/api?utm_source=blog&utm_medium=social-media&utm_campaign=bl-tellform) convinced me to make the jump.

TellForm currently uses [SparkPost’s SMTP relay](https://www.sparkpost.com/blog/setup-sparkpost-smtp-relay/) to power its user verification process through the [node-email-verification](http://github.com/whitef0x0/node-email-verification) library (which I also maintain). This works by creating a temporary user account when the user signs up along with a verification token. When the user clicks the verification link (that contains the verification token) in their email, node-email-verification copies the data in the user’s temporary account to a permanent one and saves it. If the account is not verified within a specified time (that is set in node-email-verification’s configuration), it is deleted and the verification link becomes invalid.

With SparkPost, **TellForm** has been able to grow from tens of views a day to hundreds. Furthermore, it has also allowed us to grow as an open source project.

Liked this post? You may also like our [Developer’s Email Survival Guide](https://www.sparkpost.com/resources/white-papers-guides/developers-email-survival-guide?src=Blog&pc=BL-gd-dev-survival&utm_source=blog&utm_medium=social-media&utm_campaign=bl-tellform).