My 7 yr old and I just made a little phonics reading/writing game together that we're calling Read + Write, and he and in particular his little brother who's learning to read has had a lot of fun playing it. There are no ads, no in-app purchases, doesn't track your usage or anything like that - it's very simple and uncomplicated really.
It's available for Android phones at:
Read+Write
If any of you are interested in trying it out I have a limited number of promo codes that can be used to download it for free. Just PM me or comment here if you're interested and I'll send you one. 
Hope this is ok to post here, we'd love to get your feedback!