I'm a relatively active Android developer, it's something I enjoy doing in my spare time when I have a need or idea for an app. To date I have 3 free apps on the Play store. These apps are free and do not contain ads because I don't like paying for most apps myself, I dislike ads, the money they would make is trivial, I believe in open source and have open sourced them and I don't write apps to make money. Some of these apps cost me money to run in addition to the time I spend developing them, Pebble apps alone account for 100k+ hits a day to my server. The one paid app I have on the Play store helps to cover some of the costs associated with running a server. I don't mind paying for a server all that much because I also use the server to host this website and a few other personal things. The biggest downside to free apps is the support that users expect to get.
It seems like every day there is a new cloud service that lets you store and sync your data. They all offer varying levels of encryption, security and privacy and are all priced relatively similar. Most users are perfectly fine with the limitations that come with their cloud service of choice and many are happy to use the free edition or pay a fee for the convenience of it.
I've spent 5 days hanging out and hacking with the guys at Pebble and many of the active community members and it's been nothing short of spectacular. Everyone at Pebble is extremely dedicated to what they're building and more then happy to help developers and integrate requests into the Pebble SDK. It was also an awesome opportunity to meet a bunch of developers in the Pebble community and hear some of their ideas and thoughts about Pebble.
One bit of functionality that I've wanted with my Pebble has been to lock my phone with a pin or password when the Pebble disconnects, thus securing my phone when I walk away from it. While it is possible to do this with a combination of Tasker and Secure Settings I was never really happy with the solution. It wasn't reliable and it was very heavy and hackish (services always running in the background and lots of root access). One of my biggest annoyances with some Android apps are that they unnecessarily run constantly in the background. To solve these issues for users that just want a very light app that doesn't need root access, I created Pebble Locker.