On my most recent Camino, from Madrid, I found the following apps to be valuable on a daily basis, on my iPhone 6s, and I can recommend them all highly:
(NOTE - Comparing notes with other pilgrims this year, both in April while on Camino, and while working as a Pilgrim Office volunteer in Santiago for a month in July-August, I learned that most all of these apps are also available for Android phones through the Google / Android app store.)
Guide - Wise Pilgrim Guides, including the Frances. There is a huge amount of information in this app. It rivals the better guide books, IMHO. I looked at many alternatives, but these are IMHO the best, at least until Mr.
Brierley gets the hint and comes into the 21st century. I like paper guides. It is an age thing I think. But this year, I came to fully appreciate how just one smart phone could replace an entire shelf of reference and guide books. The
Wise series is available for nearly every popular Camino route. They even offer a discounted "bundle" of Camino route apps. But, I think they cost no more than about USD 2.99.
GPS - Maps.me - once you download the requisite provincial maps and a shared Camino GPS track file, you have a very accurate routing capability, as well as a very good "between towns" mapping capability. Any guide "book" or app will necessarily have a rudimentary mapping capability. For precise mapping, outside of towns and cities, GPS is the present state-of-the-art. I tried three or four GPS mapping apps recommended here in the Forum, but found
Maps.me to be the best, easiest to learn and use, and most accurate for walking the Camino.
By way of example, in April I shared this with Raymond, a Samsung carrying Spanish pilgrim I met. He downloaded it from the Spanish Android store as we were walking, and it came downloaded with the maps he needed. Three or four "clicks" later, Raymond was fully functional. As a retired Spanish Navy officer, he was very impressed by the functionality, accuracy, and free cost. Result!
I personally liked the ability to tell me PRECISELY how many more km I had to go to reach some point. This takes the "wiggle room" out of any guide's vagaries...
Mapping & Directions - I MUCH preferred
Google Maps. I used
Maps.me between towns and cities. However, once I hit the edge of town and had named streets,
Google Maps was superb at directing me to my known address destination, usually a hostal or shop. You can change units to meters / kilometers and leave your native language. Siri's pronunciation of Spanish street names in her flat colloquial American English accent is frequently humorous, and you need to pay attention as she sounds out the names, but it was highly accurate, even walking in large cities.
Translation - God bless
Google Translate! I used it to ask for products in pharmacies or grocery stores, compose e-mails to arrange accommodations, and to obtain services. My Spanish is very basic, and not yet up to carrying on a proper conversation. So, being able to get a 97-99% correct translation is very helpful. I have used this for four Caminos over as many years. Originally, I had it on an iPod Touch that required Wi-Fi. Since last year, I have switched to an iPhone. Having "on-the-fly data" capability is much better and a big improvement in utility.
UPDATE: This year (2017) I added the
Microsoft Translator, available for Android and iOS at the appropriate app stores. A couple of native Portuguese and Spanish speakers told me that the Microsoft app results in "better" translations, especially if you are trying to write an e-mail. Evidently it has something to do with logic and assessing the context you are seeking. Anyway, I have both on my iPhone. Through experience walking from Lisbon in April and May, I tend to agree with the folks you suggested the Microsoft app might be better. Just sayin...
Weather - I prefer
Eltiempo.es+, available through the Spanish app store on Apple. It provides superior weather conditions and forecasts for virtually every named place in Spain, as well as the rest of the world. It is far better for the small towns and villages you will pass through than other available apps. This one is based on official Spanish government weather sensor sites located across the country.
Dictionary & Phrasebook - I prefer and recommend the
"iThinkdiff" line of apps. They are fully featured and VERY comprehensive. There is a free version and an inexpensive version you can buy for a nil amount, from in the app I think. Buy the inexpensive version. It has added features that are very useful.
Catholic Mass - Get
Misas.org. It is in Spanish only, and was available on BOTH the US and Spanish app store sites (for Apple). If you know the province and town / city you are in,
Misas.org will provide a list of EVERY known Catholic church, convent, seminary, monastery, hospital, senior citizens home, hospederia, etc. that has a scheduled Catholic Mass.
Masses are arranged by days of the week. There is a photo of the outside of the building. It has addresses...see
Google Maps, and even has a live link to locate the address using your native maps app. On an iPhone that is the
Maps app, which is not nearly as good as
Google Maps. But if you are a person who seeks a Catholic Mass to attend, as I do at least each Saturday evening or Sunday,
Misas.org is for you.
Transportation - Get the
ALSA bus app and the
RENFE train app. The other BIG bus line along the
Camino Frances is Monbus (Monbus.es). However, they do not (to my knowledge) have a mobile app. Their website is very difficult to use on a mobile device. When I know I need Monbus, I usually ask my place of lodging to access the site on their computer and print the necessary timetable. They can also call to make a reservation if need be.
Post Offices - Get the
Correos.es app, available through the Spanish app store. if you need to find a post office or arrange mochila transport using their new service, this app will help.
Safety & Security - The Spanish national police have developed an app named
AlertCops that allows you to register your presence and rapidly report directly to them, incidents or observations that can help prevent or interrupt crimes. AlertCops is available for both Android and Apple.
THIS IS NOT A SUBSTITUTE for calling 1-1-2 in an emergency. It is intended for registering your presence in the area, as well as reporting things like suspicious activity, a crime you witnessed, an accident, something like a wild fire in the woods, a serious and urgent safety condition (e.g. a downed utility pole across a road or the senda, etc. Anyway, the app is free. Check it out.
(NOTE: For each of these recommended apps, try your local app store. If you cannot find this or any other Spanish-native app, go into settings and temporarily change your app store country and region to Spain / España, and download the apps. Once downloaded, at least I know the Apple updater will keep all the apps updated from anywhere in the world.)
I hope this helps.