I am not an attorney, but the same mark may be used to offer different products or services that won't cross paths in commerce.
For example, Google the term DELTA and see how many different products and services come up. I just did and counted 9 on the first page alone for airline services, faucets, taxonomy, software, health related services, dental services, arts & crafts, a college, and a storage solution. All are distinctly different products and services yet they are offered under the same mark. Their channels of trade are different. If you are looking to book a plane flight, it is unlikely that you would linger too long on the Delta faucets site.
From what you've stated, it does not appear that the other party ("OP") is using the like mark to offer the same product(s). If they are not using the mark to offer mobile hand-held software, you might be wasting your time and money trying to stop their use of the mark.
In any event, it is always wise to check with a qualified attorney before going forward with anything legal. An attorney may add to or correct these statements. Thanks.