I mentioned in another thread earlier today that I am probably going to switch to an Android phone after having iPhones for the past decade. I have essentially no experience with the OS and never paid much attention to it either, but I'd see or hear things on occasion. I am looking at going with the forthcoming Google Pixel 2 after it's announced in a few weeks. But as I continue to read and watch YouTube reviews about the Pixel and Android I do have some questions. Why are there delays, sometimes very long ones, for certain handsets to get the latest version of Android? I understand that the Google phones (Nexus and Pixel) generally get the new updates immediately. But why do the handsets from Samsung, HTC and the others get delayed by the manufacturer and/or cellular carriers? Regarding the Google Play Store, is it more open than the App Store meaning susceptible to malicious apps? If so, is there a system or way of knowing how much an app can be trusted? Are there other places besides the GPS to get apps? I still have and use as my main email account the old .mac domain (firstname.lastname@example.org). Are there apps that are compatible with Apple's email where I can still use it? I do use Twitter a lot and have Tweetbot which is iOS only. I've never liked the official Twitter app, so is there an Android favorite app out there that I should consider? Thanks!