DIM is a website that can be used on any device with a recent web browser. You can get a more app-like experience on mobile or desktop by "installing" DIM through Chrome or Safari.
Hit the "share" button, then select "Add to Home Screen", or open DIM's menu and select "Install DIM". Here's a video explanation:
In the browser's address bar, click the "+" icon and select "Install". Or, open DIM's menu and select "Install DIM".
DIM can be installed directly from the Google Play app store. Or, if you already have the website open, in the browser hamburger/3 dots menu, select "Add to Home Screen". Or, open DIM's menu and select "Install DIM".
Then you need to accept the next popup.