There are both negatives and positives to having Gurbani on mobile devices...
Advantages
You can take Gurbani anywhere you go
You can do path at anytime, from anywhere
You can get bani kant at anytime, from any place. This is especially good for getting ready for keertans.
Disadvantage
Much less requirements to do path from mobile devices so it makes on lazier
No need to be tyar bar tyar while doing path (I.e no need for dastar, hazooria, washing hands when they become even sllightly jooteh) which gives less rass while doing path. Also, you can basically sit in any posture, which too makes one sleepy, and doesn't give as much rass
You can't get Darshan of physical words, which gives less rass
You become dependpent on the mobile device, which makes you do less path Kanth. Usually, one becomes dependent on the mobile device, and thus knowing that you always have the device with you, there is no need to have bani memorized.
The overall ability to get large banian memorized becomes easier, but after we become dependent on the phone, that's where the problem lye's.
What i've noticed is that with large banian, it becomes an overall disavantage to have a mobile device. One may get a bani memorized, but they will never fix the tiny errors, because they know they have a phone with them. If one did not have the phone, then would be forced to get all their bani memorized and perfectly shudh with not any tiny errors.
For small shabads, having the mobile device is a great advantage, because we can prepare shabads for keertans at anytime, anywhere.
Dass has stopped using Gutke/Senchian all together, and does all path on Mobile phone. This may not be perfectly ideal, but overall, it has helped my jeevan, but that is only because i am very lazy. In this dark age of kalyug, we need as much easy alternatives to improve our jeevans.
ਸਤਿਗੁਰਬਚਨਕਮਾਵਣੇਸਚਾਏਹੁਵੀਚਾਰੁ॥