Marketing professionals, such as myself, who look after dozens of Facebook and Twitter accounts on behalf of their clients don't keep logging into each account in turn, via a web browser or a phone app. Instead they use an aggregator that shows them the current feeds from all those accounts on a single screen. The best-known of all such aggregators is called Hootsuite and, although it costs money if you want to access dozens of social media accounts, you can look after 3 for free.
Hootsuite is web-based, so you don't need to download anything. Just sign up with an email address, and click to allow it access to your social media accounts. Then log into it whenever you wish. Or if you don't like it, just go back to accessing your accounts via the previous method and everything will still work just fine. You can even mix and match, using Hootsuite sometimes and individual browser windows whenever you prefer.