I'll tell you, the first time you start and stop your sprinklers from inside your house using your phone is a real kick.I decided to try one of these out, because I'm tired of spending the better part of a day moving the hose around the lawn to get good coverage. I started in the back yard, laying hose and putting out 3 Hunter bodies with MP Rotator heads. Then I connected them to this BTT timer, and it works like a charm. Now, I can water at ideal times of day without having to set the alarm clock for crazy time, and when it's time to overseed, it will be very easy to water for 10-15 minutes every morning with zero effort. It's like having a $3000 in ground system installed, but for a small fraction of the cost (although the sprinkler bodies and hoses are above ground - which makes them easier to maintain, so you decide if that is a plus or a minus for you).Bottom line, I'm happy and will be giving my front lawn and side yard the same treatment in the coming weeks, before the hot weather arrives.The app will connect to multiple timers. It also has a fair amount of flexibility for setting your scheduling, though it's not the most intuitive interface ever devised. However, if you are willing to dig through it, it can set a schedule based on days of the week, or on a cycle of days (water every 3 days for example, regardless of what day of the week it is). You can set up multiple run times during the day. You can set it to cycle periodically based on time rather than days (every 3 hours for example). You can also set it to cycle on and off over a defined window of time (run for 15 minutes, stop for 5, repeat, for two hours every morning for example).It rains often where I live (though accumulation is almost never adequate in a week) so this next feature is important: You can suspend the schedule for a selectable number of days. So if we get 1/2" of rain, I can suspend the schedule for 3 days, and it will return to it's normal program afterwards.Of course, you can run this manually, for a selectable period of time. You can also run it manually by physically pressing a button on the timer and it will run for an hour and shutoff automatically. There's probably more capability here, but that's what I've explored so far.A couple nice features in the interface: you can customize the name of each timer and for this model with two outlets, you can customize the name of each outlet (timer=back yard, zone 1=grass, zone 2=shrubs drip) and you can even add pictures to those zones so it's really easy to identify which area you are working with when programming.This does run on two AA batteries. I do not know what the battery life will be like, but after about 5 days running on rechargeables, they are down 2%, so you should have no problem getting a full season out of a set of batteries, especially if you aren't often connecting with the phone to fiddle with them.There are only a few minor things I'd like to see improve in the next generation of this product, or in future app updates:1. I'd like the app to have a more intuitive design that uses a more plain language approach so that anybody can set their timers up without having to figure out what the different options mean.2. I'd love to see a slightly more robust bluetooth transceiver on this. The range is limited. I believe the product says 30', but I lose connection about 20' away, and if I am inside, I need to be within about 10' to connect. I know this is a trade-off between battery life and range, but I'd be happy replacing the batteries every 2 months if I could sit on my recliner and connect to various timers on different sides of my house. Maybe another option would be to offer an accessory hub that plugs in somewhere in the house and can extend the signal reach.Overall, I'd say this is a major improvement over other programmable timers I've used, with more options and easier programming. Being able to suspend scheduling or manually water from inside the house is a godsend.Highly recommended.