I have plenty of Bluetooth devices and multiple Apps, but the beauty of the UltraGauge is it is hardwired, application specific and automatically sleeps and starts. If the UltraGauge does not start, then there is a charging problem. I can set either high or low threshold alarms for Voltage, Temperature, Fuel Level or for any other parameter the UltraGauge monitors.
I put a charger on the car maybe every 6 weeks depending on how I am using it. I am still floored that a no charge event in my case has NO indication. You will only know once the sub modules start to fault out, in my case it the as the All Wheel Drive system when into error.
Something like a bigger Battery Tender is not a bad thing to consider, not too large and they have quick connectors. The small wall wart Battery Tenders are incapable of doing a good job on larger batteries that are heavily discharged, so I would go with something larger like this unit -
Battery Tender® 3Amp Power Plus!
Note it is has limited availability, Costco and Battery Tender Web Site.
I will hopefully have my Voltage regulator tomorrow or Tues, but with temps in the 20F range, not highly motivated to replace it until I have a some nicer weather.