Finally, and most annoyingly, getting set up with On Voicefeed was pretty tedious. You have to enter basic information, just like almost any other app, which is fine. But then you’re asked to enter a security code that is sent to you by text. At this point, I’m thinking, “Alright, but this better be it.” Then, the app asked me to call a number that was automatically added to my contacts in order to activate the account. Fortunately, that was the end of it, but I was still a little peeved at how long it took to get started. I’m sure that some of those steps are necessary to tap into your voicemail, but finding a way to streamline the process would be much appreciated.
A professional voicemail should be short and succinct. Simply introduce your company, ask the caller to leave their information, and let the caller know when to expect a callback. Once you record your greeting, you can easily upload it into the OpenPhone app. Simply go to your phone number’s settings, then choose to record a greeting, upload an mp3 file, or use text-to-speech.

You could also just choose to create a fun message for all of your friends in your running group, for example:
If the you haven't changed your personal greeting, a default system greeting will be played for callers. For example, "Please leave a message for John Smith. After the tone, please record your message. When you finish recording hang-up or press the pound key for more options."