On a PC: Simply drag the button to your browser's bookmarks bar (Chrome, Firefox, Safari, Opera, etc.).
On a mobile device: Chrome for Android synchronizes your bookmarks with the PC, so ISeePass should automatically appear on your device. On other mobile browsers (such as Firefox), long tap the button and select Bookmark Link.
Free and open source
ISeePass is free and open source, and licensed under the GNU General Public License v3.0. You can use it without charge, even for commercial purposes.
Read the license
Check out the source code
ISeePass' source code is available on GitHub. Star and fork the repository, experiment, contribute, and get in touch if you think you can help out!
View the source code