Free and useful apps for startups

I wanted to make a list of useful apps and services that I use or have used for any on my startups. This list will only feature apps that have a free plan.

• Mailchimp for email campaigns. They offer a generous free plan that has always been sufficient for all my use cases.
• Buffer for social network sharing. The free plan includes only a single Twitter account, but if you have enough willpower you can always use separate logins for each of your Twitter account. Also they premium plan is pretty cheap - 10$/month.
• UserVoice for a feedback portal. It is easy to setup and theme, always been pleasant to use. Can use it as a help desk app or just as a feedback widget.
• Google Docs to create and share documents. I have never wanted a full office suite, because Google Docs are perfect for me. They are fast, simple and already synced in the cloud. It is easy to collaborate on the docs and share them via email. This is one of my most used services overall.
• HipChat for instant messaging. Currently free for unlimited users, this is a pretty decent app for group chat. There are some cool integrations with other services, that I found to be quite useful. It has a web, mobile and desktop version.
• GitHub for public code hosting. GitHub is the De Facto standard for open source code hosting. I am often working on open source projects, so I am a daily user of GitHub. The free plan covers everything that is public. If you want a private repository, you need to pay up.
• TeamCity for Continuous Integration. TeamCity has a free plan and can be self-hosted on your own server. I use it for Datazenit and couldn’t be happier. It is a polished product, as one could expect from JetBrains.
• Hiburo for task management. A simple task management app in the cloud that has a free plan for a single user. Disclaimer: I am one of the co-founders at Hiburo.
• Dropbox for file hosting and syncing. Even though the free plan has a limited space (2GB), Dropbox is so popular that you probabaly are already using it. Due to the space limitations I also use Google Drive, that should have had 15GB of free space, but somehow I ended up with 60GB.
• PayPal as payment processor. There is a lot of hate for PayPal, but I really haven’t found a better alternative to it. I live in Latvia (Europe) and here we have less payment processors than in USA and Western Europe, so that’s probably one of the reasons I am sticking with PayPal for Datazenit. I have used payment gateway that lets you accept credit cards directly on the website for GetSSL.me, but I was not satisfied with the service and many customers have complained that they would better like to use PayPal or an outside service because of trust issues with a smaller and relatively unknown company like GetSSL.me, and I can fully understand them.

If you want to suggest a service or an app, please leave a comment.