When I log into my corporate O365 account, I get the screen with apps I have access to. When I click on the SharePoint app, it does not take me to my corporate SharePoint Home page (https://avistapharma.sharepoint.com/Pages/Home.aspx) it takes me to a page (https://avistapharma.sharepoint.com/_layouts/15/sharepoint.aspx) that shows me the last few sites I've visited on my corporate page. I need to change the URL so that when I click on the SharePoint app, it takes me directly to my corporate home page. Does anyone know how to do that?
Unfortunately, this tile and other OOTB tiles app launcher experience is controlled by Microsoft. So we dont have the ability yet to modify the tiles or its behaviour other than of course the theming(color) part.
So we will have to wait till MS (and if) provides us the capability to change the experience. (IMO, not anytime soon).
One thing you can try is by adding your custom tile to the app launcher using global admin credentials. Unfortunately, this cant be pushed to all users, yet, so each user will have to individually pin the tile once admin after admin has added to the app launcher.
As mentioned by Gautam, the SharePoint tile cannot be changed. Another thing you can do if you are the global admin is to add your company logo to the office 365 suite bar at the top and add the link to your SharePoint intranet to the logo.
Here is instructions on how to do that https://support.office.com/en-us/article/Customize-the-Office-365-theme-for-your-organization-8275da91-7a48-4591-94ab-3123a3f79530
The advantage is that wherever a user is on office 365, if they click on the logo, it will take them to your company SharePoint homepage.
Please note that if you leave the option "Prevent users from overriding theme" unchecked, a user can override this logo if they choose their own theme.
In general, a logo with transparent background works best.