It's not necessary to use RStudio to use shinyapps.io, it's just a bit easier. You need to follow these steps:

1. If you're happier in another IDE, you just need to ensure that you have the latest version of devtools installed:

    install.packages('devtools')  

2. Install shinyapps:

    install_github('rstudio/shinyapps')  

3. Load shinyapps:

    library(shinyapps)  

4. Log into your shinyapps.io account, copy the authorize token command from the tokens menu (token marked with Xs here), and run it in your R session (note that this only has to be done once on each computer):

    shinyapps::setAccountInfo(name='chrisbeeley', 
      token='XXXXXXXXXXXXXXXXXXXXXXXX', 
      secret='XXXXXXXXXXXXXXXXXXXX') 

5. Set your working directory to the folder that holds your application:

    setwd("~/myShinyApp")  

6. Deploy:

    deployApp()