HarmonySite has a companion app, available for both Apple and Android phones and tablets:
The purpose of the app is to complement the functionality of the HarmonySite Members Area, by providing quick access to some features that are most useful in a hand-held device, so you don’t need to log into your HarmonySite website via your phone’s web-browser for such tasks.
The app provides functionality for group MEMBERS. Group admins continue to do all their administration tasks from the website – there are no admin tools within the app.
The HarmonySite app is FREE for users to download and install. However, for it to work with a HarmonySite, the group will need to purchase an annual subscription to the app. It’s not expensive – usually less than $1 per user per year. See exact pricing.