This app was mentioned in 20 comments, with an average of 2.80 upvotes
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
If you're on Android.
The Dev is awesome. You can also turn off ads for free but donate if you like the app!
Edit: /u/diceroll123 is the dev BTW. Really friendly dev.
There are a couple of Android apps (maybe also for iOS but I don't use iPhone) that have all that info, and they are offline!
Edit:
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth (my favorite)
And
https://play.google.com/store/apps/details?id=com.poyo.boirebirth
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
I'm a big fan of this app. Fairly easy to use. I think most of the info comes from the wiki, but this is a bit cleaner, if less in-depth. You can search for specific items as well as browse through the lists and it has a checklist of the achievements. No clue if it's available on iOS
And remember, you're gonna die loads of times. That's fine. I played the game 200+ hours on pc and now started playing again on the switch. I still cannot consistently beat all bosses, you'll die and that's fine. Next run you might get a bit more lucky with better items.
Oh, as everyone keeps recommending to use platinumgod (which is great), there are also apps on all mobile platforms. I found that Guide for BOI: Rebirth + Afterbirth is a great android app. You can filter quickly on room type for items, so you only see items of the devil rooms. Makes finding the items just a bit more quick. (I'm in no way affiliated with this app, I just like it a lot.)
For the items you can use the wiki or the app I personally use https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth and for the synergies you can search directly to google
I use this app : https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
It even has Antibirth for now (will be replaced by Repentance upon release) I hope it'll help some players ^^
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
I think this is what you are looking for and even though it says rebirth guide it is updated for afterbirth +. It's a very good app. I found it on here one day after the creator posted it. Unfortunately I don't remember their Reddit user name or I would link them.
Edit: here is the original app thread by /u/diceroll123/
If you have android this is my favorite app to use while playing, it's helped me a lot. (I'll never remember dice rooms)
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
If you have android this app is easily one of the best https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth you can look up anything and it will tell you exactly what it does
I must also commend you on your choice of icon packs.
I use this : https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
It is WAY more convenient than platinumgod and doesn't need me to sit at a computer.
this is the one I use.
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
Pretty consistently updated. Lets me track my completion marks.
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth i used this before i know of external item description! Maybe it will get the repentance update
I've got an Android phone and this is the one I use.
https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
Google playstore link: https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
I use this app. It's fantastic. https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
No clue, try checking a guide maybe? One I've been using is https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth
Pretty sure there's an iOS one too.
This is a great app for isaac info, you can search by color or item pool https://play.google.com/store/apps/details?id=slaughter.guideforbindingofisaacrebirth&hl=en&referrer=utm_source%3Dgoogle%26utm_medium%3Dorganic%26utm_term%3Dbinding+of+isaac+on+android+play+store&pcampaignid=APPU_1_ohSzWuzqIMuWsAXcrJXIDQ