The swell is a solid mod. Prices aren't the best right now, I'm sure they'll be back on sale at some point. Wasn't sure what to expect with a 'plastic' mod but it's actually quite nice. More of a solid nylon, mine has the textured g10 fiberglass panels. Lightweight, sturdy feeling, comfortable in the hand. No button rattle, no play in the doors. Water resistant. Various modes, variable wattage, wattage curves, variable voltage, bypass, tc (takes some fiddling but works ok). The ability to turn features/modes off you don't use.
I'm not a big phone app person but once dicking around through the tedious shit the app does work (at least android, I don't have an iphone). All the advertised features work like the proximity alarm, mod finder. I don't use the app much but might be easier to adjust settings from the phone for some.