What I do: put away my Android 5.5 inch screen phone for a second. Using my old iPhone 5s with a broken home button, open Google Photos where I have the pictures I need to email and send it using not gmail app, since it won't cut the size either, but mail app using gmail account.
Before releasing the wrath saying this aint the answer you were looking for or this is not an answer, allow me to explain myself, because this might be an answer for those who are like me and believe some functionalities just should be there and substituting them with apps from unknown sources just might not be a good solution.
I don't like downloading extra software containing ads (after some were firing full-screen ads right after unlocking the screen). I dont like third party apps that for no reason get access to my library. Nor do I like using them to browse through all my phone to find photos I need to email after I already nicely arranged them by albums in Google Photos and they are all in one place. Yes, Android is awesome. But iOS is good too for certain things.
I beleive that nowadays many can afford to have at least an iPhone 5 (used are very cheap) which is fast enough for functionalities that are not native to Android. Especially since iOS can easily sync with Google accounts and apps.
So I suggest to finally stop this: hey I am a Mac and I am a PC dillema and say, yes, I do use Windows when I want to play the Witcher 3, but I do use Mac for work. It's the same with Android and iOS. Yes Android is 100 times more flexible and convenient than iOS. But I do prefer some things to do on iOS devices since it's much faster and just works.