If you want to make your photos look great, there’s no app that I’d recommend more than Snapseed. Yes, the app has a bunch of vintage filters if you’re into that sort of thing, but there are so many ways you can edit your photos using Snapseed beyond mere filters. Selective Adjustments are a key feature that really separate Snapseed from competitors because it allows you to take complete control of your photos. There are even OS X and Windows versions of the app so you can use it on your preferred platform. Don’t let the $4.99 price tag scare you away because Snapseed for iPhone or iPad is worth every penny.
A simple chat (slack style) it's enough. Just having the possibility to send messages either single user or team (#channel). But please don't forgive to give an useful appeal to mobile app (worst error of competitors is, have a good app but totally no mobile friendly!) i would expect to have a similar whatsapp or slack app for messaging within the slack mobile app!