A method supporting identity verification for an end-user, the method comprising: sending a link, which directs an end-user to a software functionality, such as but not limited to a web application, native app/native sdk, web app desktop, web sdk, which is operative for end-user identity verification, to an end-user's mobile phone, thereby to open an identity verification session when the end-user clicks on the link; and via the software functionality activated by the end-user's clicking on the link, eliciting data from the end-user, wherein the software functionality processes at least one image captured by at least one end-user's cellphone during the session or in real time or near real time, and for at least one image so captured, detects, and communicates to the end-user that the image is of unsatisfactory quality characterized by at least one of: said data comprises an image of at least a portion of an ID document borne by the end-user; and/or the software functionality processes at least one image captured by at least one end-user's cellphone during the session e.g. in real time or near real time, and for at least one image so captured, detects that the image is of satisfactory quality and, responsively, provides a binary indicator whose "satisfactory" value indicates to the end-user that the image is of satisfactory quality, thereby to encourage the end-user to confirm or upload the image to the software functionality; and/or the software functionality sends to the end-user's mobile phone an image of a rectangular outline, during the session, within which an image of the end-user's face is to be positioned; and/or the link is sent to the end-user's mobile phone via SMS. sending a link, which directs an end-user to a software functionality, such as but not limited to a web application, native app/native sdk, web app desktop, web sdk, which is operative for end-user identity verification, to an end-user's mobile phone, thereby to open an identity verification session when the end-user clicks on the link; and via the software functionality activated by the end-user's clicking on the link, eliciting data from the end-user, wherein the software functionality processes at least one image captured by at least one end-user's cellphone during the session or in real time or near real time, and for at least one image so captured, detects, and communicates to the end-user that the image is of unsatisfactory quality characterized by at least one of: said data comprises an image of at least a portion of an ID document borne by the end-user; and/or the software functionality processes at least one image captured by at least one end-user's cellphone during the session e.g. in real time or near real time, and for at least one image so captured, detects that the image is of satisfactory quality and, responsively, provides a binary indicator whose "satisfactory" value indicates to the end-user that the image is of satisfactory quality, thereby to encourage the end-user to confirm or upload the image to the software functionality; and/or the software functionality sends to the end-user's mobile phone an image of a rectangular outline, during the session, within which an image of the end-user's face is to be positioned; and/or the link is sent to the end-user's mobile phone via SMS. said data comprises an image of at least a portion of an ID document borne by the end-user; and/or the software functionality processes at least one image captured by at least one end-user's cellphone during the session e.g. in real time or near real time, and for at least one image so captured, detects that the image is of satisfactory quality and, responsively, provides a binary indicator whose "satisfactory" value indicates to the end-user that the image is of satisfactory quality, thereby to encourage the end-user to confirm or upload the image to the software functionality; and/or the software functionality sends to the end-user's mobile phone an image of a rectangular outline, during the session, within which an image of the end-user's face is to be positioned; and/or the link is sent to the end-user's mobile phone via SMS.