I am using TexStudio as my LaTex IDE and honestly speaking I find it better than others available for the same purpose. One of the advantages is that you can use dictionary for spell checking and in contrast to TexMaker (which is the main source code on which the TexStudio is built) you can also add words in the dictionary. I use my office computer as well as my laptop to write my thesis and I wanted that if I add a word using my office computer TexStudio it also get added to my laptop dictionary as well. I figured out that the best way to do this is if I can make the same dictionary access to both the computers. So I used the Dropbox to store the dictionary files. TexStudio works with the OpenOffice dictionary. So here are the steps to make the dictionary work in TexStudio.

Step 1: Download the OpnOffice dictionary (http://extensions.openoffice.org/en/project/english-dictionaries-apache-openoffice). The download file will be an .oxt archive, which can be open using any archive manager. Extract the en_GB.aff and en_GB.dic files (I am using English Great Britain).

Step 2: Create a folder in Dropbox say dictionary and move the extracted .aff and .dic file to this folder.

Step 3: Now open TexStudio and click on the menu Options > Configure TexStudio.

Step 4: On the General tab look for the section Dictionaries. And give the path to the dictionary in the Dropbox folder. It will automatically show the dictionaries available in that folder for you to choose. And you are done.

Note : The OpenOffice dictionaries actually do not add the word in the main dictionary file but instead it creates another file with the extension .ign. This file contains the list of the words which user has either added or ignored during the spell check. To add a word in the dictionary you have to right-click on the word and choose ignore always option. This will add the word in the ignore list and next time when you will open the document that word will not be marked as a spelling mistake. The advantage of putting the dictionary in the Dropbox folder is that when you ignore a word using one computer it will also be updated on the other computer, hence the same dictionary and ignore list can be used on multiple computers.