FlySo is an app that lets you manage your Facebook, Twitter, and Instagram accounts from one single interface. How is this possible? Well, what FlySo does is basically use the webview versions of each social network. This means you can use Facebook or Twitter without any problems, but you can't upload any photos to Instagram.
In the left tab you have your Facebook account, while in the center tab you have Instagram, and on the right you have Twitter. From the Facebook tab, aside from updating your profile and seeing your friends' posts, you can also talk with your contacts without needing to have Facebook Messenger installed.
The main drawback of using FlySo is when it comes to using Instagram. You can look at all the posts of all the users you follow, check out user profiles, give likes, etc.; but you can't upload any photos.
FlySo is a very interesting app if you're looking to reduce the number of apps you have installed on your Android. In this lightweight app of only 2.5 megabytes, you can find practically all the same features as Facebook, Facebook Messenger, Twitter, and Instagram, all in one app.