I am a college student, that has been making apps on the side since the release of Swift. You don't hear that every day. I am trying to put myself through school, while doing what I love on the side. I have 2 accepted apps on the App Store under my name, have collaborated on other apps that are on the app store, have made a few that aren't on the app store yet, and also, I am the COO of the app Shoe Swap, which is growing rapidly. I know the process of getting accepted into the app store, I know how to develop to meet Apple's very strict guidelines, and I learn quickly if there is something that I do not know. I look forward to working with you!
As far as the other bids that are quite low, and quite frankly, within your budget, you are going to struggle with communication and quality of work. I am here to offer you work at the appropriate rate, all while giving you the quality you are paying for.
As far as your app idea, I assume that the tags you are talking about are bluetooth tags that would for example, be on dogs collars and you would like to track if they are out of a certain range, and if they are, you would get notified that your dog is out of the range you set. If that is the case, working with bluetooth requires me to work with a few frameworks, as well as, working with bluetooth devices, which can be quite a pain sometimes. Making the user interface , as well as getting accepted in the app store are 2 separate portions of the project which the price will be TBD.