If you only use it to view, not post, I very much recommend Barinsta [0] - it's a fully-featured FOSS alternative client with every feature of the official client and more.

Edit: god damn it, they got a C&D: [1]

[0] https://f-droid.org/en/packages/me.austinhuang.instagrabber/ [1] https://news.ycombinator.com/item?id=27969379