Simple Mobile apps have been very popular among FOSS enthusiasts. I've personally been using the Gallery, Contacts and the Phone app since a few years now. It's a shame that it has come to this, will be on the lookout for their forks.
So the owner claimed in the article that any data tracking added would be opt in. I looked at the settings and found error and usage tracking hidden under an advanced button at the bottom of the settings. It was enabled and I don't remember ever being asked about it (or else it would have already been disabled because I never opt in to that shit).