Creating an app for Garmin 1000 displaying "feed time" alerts WITH a message

To the experts

I queried in another about an app (Garmin 1000 capabilities) capable of alerting the user with a “feeding time” with what to take. It looks like there are a couple of existing ones but they of give you only an alert or one needs to consider a smartwatch. So the question are:

Could one have a (Garmin 1000) app which capable of alerting the user (at a pre-defined) time AND give a word stating to what to take?

Something like that

Alert every 15 minutes ; Message – Drink

Alert after 30 minutes ride; Message – Take Banana

Alert after 60 minutes ride; Message – Take Gel

Alert after 90 minutes ride; Message – Take XXX

And so on

The way I see it a simple “table” of fields in the settings

Time : Msg

 

How difficult would it be to code such thing?

While I do some occasional coding for work I have never done any app. What does one needs to do such thing? Where do I start? 

If someone is willing to have a go (it may only be a couple of hours work  for all i know!) then feel free to get in touch

 

Thanks

Regards