Salesforce custom button code to increase a number field by 1 which can be uses to fire off a process builder. Confirmation from the users and system admin users have been added.

AccountCustomerButtonIncrease

//I am assuming this code allows for the JS SOQL calls
//Check the resources section for SF documentation
{!REQUIRESCRIPT("/soap/ajax/29.0/connection.js")} 
{!REQUIRESCRIPT("/soap/ajax/29.0/apex.js")} 

//Yes or no popup dialog box to confirm from the users
var answer = confirm("Are you sure you want to create a opportunity?")
//Check if system admin and yes was selected on modal box
if (answer && '{!$Profile.Name}'== 'System Administrator'){
//Select the current account records and put it into the record variable
var records = sforce.connection.query("SELECT Id, Process_Builder_Trigger__c FROM Account Where id = '{!Account.Id}'"); 

//The records object come with other garbage so we need to only pull out the account we are working with
//Pull the account object out of the records variable and set it to accountRec
var accountRec = records.getArray('records')[0]; 

//Increase accountRec Process_Builder_Trigger__c 
//JS sees the number field as a string so this will make sure that is a number - Number(accountRec.Process_Builder_Trigger__c)
accountRec.Process_Builder_Trigger__c = Number(accountRec.Process_Builder_Trigger__c) + 1; 

//Update accountRec object 
sforce.connection.update([accountRec]); 

//Reload the page 
window.location.reload();
}

It's a good idea to check the result before reloading the page.

      var result = sforce.connection.update([oppRec]);
      if (result[0].success === "true") {
        window.location.reload();
      } else {
        alert(
          "An Error has Occurred. Error: \r\n" +
          result[0].errors.message
        );
      }