Thanks for the response, Kelly. Yes that is the same template application I am using. Like you, I just downloaded the code from the github repo and installed locally. The items in the default sample group do open in the same window for me, but when I change the group ID to the AGO group I am using in my application, I get the same problem. I am wondering if its because my group is full of custom applications hosted on my web server, rather than web maps. Haven't tested in anything but Chrome but will try other browsers now.
This is my application:
http://summitmaps.summitoh.net/WebAppGallery/
Here is my options.js.:
define([], function() {
var config = {
"group": "1a13ba1acc6843578577c32ac823bcc0",
"appid": "",
"theme": "blueTheme",
"siteTitle": " ",
"siteBannerImage": "images/seal_Black_Blue.png",
"mapTitle": "",
"mapSnippet": "",
"mapItemDescription": "",
"mapLicenseInfo": "",
"homeHeading": "",
"homeSnippet": "",
"homeSideHeading": "",
"homeSideContent": "",
"footerHeading": "",
"footerDescription": "",
"footerLogo": "images/MapsandAppsLogo_PMG.png",
"footerLogoUrl": "https://summitgis.maps.arcgis.com/home/index.html",
"addThisProfileId": "xa-4f3bf72958320e9e",
"defaultLayout": "list",
"searchString": "",
"sortField": "modified",
"sortOrder": "desc",
"searchType": "",
"mapViewer": "simple",
"paginationSize": 2,
"galleryItemsPerPage": 9,
"showProfileUrl": false,
"showSocialButtons": false,
"showFooter": true,
"showBasemapGallery": true,
"showArcGISBasemaps": true,
"basemapsGroup": {},
"showGroupSearch": true,
"showGroupSort": false,
"showMapSearch": true,
"showLayerToggle": true,
"showLayoutSwitch": true,
"showOverviewMap": true,
"showMoreInfo": false,
"showPagination": true,
"showExplorerButton": false,
"showArcGISOnlineButton": false,
"showLicenseInfo": true,
"showAttribution": true,
"showComments": false,
"showRatings": false,
"showViews": true,
"showMobileButtons": true,
"openGalleryItemsNewWindow": false,
"bannerBackground": "images/ui/pmg_banner_map_app.png",
"proxyUrl": "",
"sharingurl": "",
"iosAppUrl": "itms://itunes.apple.com/us/app/arcgis/id379687930?mt=8",
"androidAppUrl": "https://market.android.com/details?id=com.esri.android.client",
"pointGraphic": "images/ui/bluepoint-21x25.png",
"sourceCountry": "USA"
};
return config;
});